The brand new metro, Denver Eagle P-3 Commuter Rail Service, connects the airport and other outlying districts of Denver with the central Denver Union Station, adding over 40km of new routes to the existing light-rail system.

The WiMAX system deployment has been completed on the first and largest of three corridors, the "University of Colorado A Line" to Denver International Airport, with two additional corridors, "Gold Line" to the Western suburbs and "Northwest Corridor" scheduled for service by the end of this year.

Challenges

The new metro required a connectivity solution which could support the following operational applications and systems:

Positive Train Control (PTC)

Passenger Emergency Intercom (PEI)

Closed Caption Television (CCTV)

Maintenance Data System (MDS)

Public Announcement and Visual Message Sign (PA/VMS) systems.

Through an innovative, strategic partnership with Xorail, Nomad designed and tested a WiMAX communications solution to deliver a train-to-wayside WiMAX network to meet the customer’s expectations.

The creation of a secure, reliable radio network connection, with high levels of redundancy, is extremely complex. It requires multiple parallel systems to ensure that if any one element of the network connectivity fails, the system remains operational.

This is facilitated through the creation of two private parallel radio networks, using Nomad’s CCU router aggregation software to pass traffic over any available radio route. This combination of parallel trackside networks with multiple on-board radios and redundant routers delivers a robust connectivity solution.

Solution

Nomad has taken the project from an initial concept stage and designed and developed the unique trackside to on-board communications solution for Xorail, providing an integrated signalling solution for Denver Transit Partners.

The system leverages Nomad’s IP technology and connects the fleet of railcars to 50 trackside WiMAX transmission sites arranged to give multiple redundant operation, and so maximum availability.

Xorail (Wabtec Corp.), US

Implementation

The partnership extended to Nomad’s onsite visits to commission and test the 68 rail cars which were being put into service. This testing included generating various ‘failover’ scenarios in the multiple redundant network, taking train radios and routers out of service and confirming the resilience of the system.

Results

Crucially these innovative solutions support operationally critical rail signalling communications in North America. The system enhances operational efficiency and reduces down-time and carriages being out of service.

The resounding benefit to the transportation operator is improved fleet optimisation. Most importantly, the communications system complies with Federal Railroad Administration standards for positive train control, a mandate that requires every rail system to provide an automated service that has a train stop safety capability in case of loss of communication with the centre.